Skip to page body Home Customer Service How To Environment Projects & Programs About Us

Wastewater Service Charge Appeal

Our Wastewater Service Charges cover the cost of collecting, transporting, treating and disposing of each unit of wastewater discharged into the sewer system. Wastewater service charges are calculated by multiplying water consumption by an assigned flow factor.

What is flow factor?

The flow factor is the percentage of metered water use returned to the sewer system as wastewater. For purposes of determining applicable charges, the percentage of water use returned to the sewers (flow factor) is assumed to be 90% for single-family residential users and non-residential users and 95% for multifamily residential users.

Water Use Restrictions

In response to California’s continued drought and the recent emergency water use regulations imposed by Governor Brown and the State Water Resources Control Board, on May 26th the San Francisco Public Utilities Commission (SFPUC) approved the 2015-2016 Drought Programs to achieve a 10% retail system-wide water use reduction for the SFPUC. The Drought Program calls for a 10% reduction in water use by all customers; increases the mandatory reduction in water use by dedicated irrigation customers from 10% to 25%, adjusts existing reduced wastewater flow factors to reflect a 25% reduction in irrigation usage, and impose additional mandatory restrictions on outdoor water use as required pursuant to the State Water Board’s Emergency Regulations.

Accordingly, customers with reduced flow factors will have their flow factor adjusted to reflect a 25% reduction in irrigation usage effective July 1, 2015 and it will remain in effect until the water shortage emergency is lifted by the SFPUC General Manager.  Furthermore, this 25% reduction of irrigation of water use will also apply to new wastewater flow factor appeals received during this restriction period.

The flow factors will be adjusted as follows and will be rounded down to the nearest whole integer.

For single family residential and non-residential customers:

Adjusted Flow Factor = (90% - Reduced Flow Factor) x (% Mandatory Reduction) + Reduced Flow Factor

For multi-family residential customers:

Adjusted Flow Factor = (95% - Reduced Flow Factor) x (% Mandatory Reduction) + Reduced Flow Factor

An example of a flow factor adjustment is provided below:
A single family residential customer currently has a flow factor of 80%. A 25% mandatory reduction on irrigation usage is in effect.

Adjusted Flow Factor = (90% - Reduced Flow Factor) x (% Mandatory Reduction) + Reduced Flow Factor
= (90% - 80%) x 25% + 80%
= 82.5%
= 82% (rounded down to nearest whole integer)

Residential Appeals
Residential users may be eligible for a reduced flow factor if they are using large amounts of water to irrigate a lawn or garden and believe their annualized irrigation consumption is greater than 10%. Customers may request that their flow factor be reviewed by filing an appeal for a reduction of their sewer service charge.

Appeals should be submitted to:

San Francisco Water, Power and Sewer
Customer Services, High Consumption Unit
525 Golden Gate Avenue, San Francisco, CA 94102

Each appeal form must contain the name and address of the residential user and a statement that substantiates the percentage of incoming water discharged to the sewer. All customers will be notified in writing of the department’s decision. For questions regarding residential appeals, please contact the High Consumption Unit at (415) 551-4780.

Customers may also appeal to be exempted from the flow factor adjustment if any of the following criteria apply:

  1. A residential customer with irrigation demand consisting of 100% edible plantings for individual consumption or commercial purposes; or
  2. A non-residential customer with a reduced flow factor due to non-irrigation water use such as cooling towers.

For more information about the drought and recommendations for efficient landscape watering practices, please refer to efficient landscape watering tips or visit

Non-Residential Appeals
Non-residential customers who want to appeal their sewer service charge should contact the Bureau of Environmental Regulation Management at (415) 695-7310.

Free viewers are required for some of the attached documents.
They can be downloaded by clicking on the icons below.

Download Acrobat Reader Download Flash Player Download QuickTime Download Windows Media Player Download Microsoft Silverlight Download Word Viewer Download Excel Viewer Download PowerPoint Viewer
Last updated: 7/2/2015 12:01:57 PM